[174] The Army's
principal missile team was formed around 120 German rocket experts
brought to the United States in 1945. First stationed at Fort Bliss,
Texas, the Germans were transferred to the Army's Redstone Arsenal,
Huntsville, Alabama, in 1950; and they were soon deeply involved in
the Army's growing missile development program. The technical group
was headed by Wernher von Braun, who had held the same position at
Peenemijnde during the development of the German A-4 (V-2) rocket,
the beginning of modern rocketry.4

[175] The first large
Army ballistic missile was the Redstone, modeled after the V-2.
Redstone was powered by a North American Aviation rocket engine
developing 334 kilonewtons (75 000 lb thrust) using an alcohol-water
mixture and liquid oxygen. During eight years of research and
development and 37 flights, the Redstone evolved into a
322-kilometer-range vehicle, 21 meters tall, 1.8 meters in diameter,
weighing 27 670 kilograms at launch.5

A space enthusiast since youth, von Braun
proposed a satellite launch vehicle based on Redstone in 1954, a year
after the first Redstone launch. In 1955, his team submitted a
proposal for a satellite launch vehicle to the Department of Defense.
Called Jupiter C, it consisted of a modified Redstone with two
solid-propellant upper stages. This design was used in a joint
Army-Navy proposal to the Stewart committee, but it was not selected.
Disappointed, von Braun soon found another application-study of
aerodynamic heating of a warhead reentering the atmosphere during a
ballistic trajectory. Three Jupiter Cs were launched, the last less
than two months before Sputnik I. After this flight, the commander of
the Army Ballistic Missile Agency (ABMA) at Redstone Arsenal, Maj.
Gen. John Bruce Medaris, ordered the remaining Jupiter equipment into
storage. As enthusiastic a space proponent as von Braun, Medaris was
waiting for the right opportunity to show what ABMA could do in
spaceflight.6

The perfect opportunity soon came. Medaris and
von Braun were dinner hosts to visiting Neil McElroy, who was
succeeding Charles Wilson as Secretary of Defense, when word came
that Sputnik I was launched. The rest of the evening and the
following morning were devoted to what ABMA could do. On 31 January
1958, the Medaris-von Braun team launched Explorer I, first American
satellite, using a modified Jupiter C vehicle.*

* It consisted of a modified Redstone first stage and
three upper stages of solid rockets. The three upper stages used
11.6, and 1 Sergeant solid rockets, respectively. The Sergeant, 11 cm
in diameter, was developed by the Jet Propulsion Laboratory, which
teamed up with ABMA in building and launching the first satellite.